Detonating fuse



Sept.- 7 1926.

R. MALLET DETONATING FUSE Filed April 22, 1924 xw m n mm W7, M M L Patented Sept. 7,' 1926. I

UNITED, STATES PATENT or I RICHARD MALLET, OF PARIS, FRANCE, ASSIGNOR T SIMSBURY, CONNECTICUT.

The fuse br as to give good results, it is difiicult to transmit F I C E THE EN'SIG-N IBICKIORD (70., OI

DETONATING FUSE.

Application filed April 22, 1924,

difliculty of connecting a secondary anch to the main detonating fuse, so is well known, i. e., an explosive wave from the main fuse to the secondary fuse with certainty, especially when a fuse prepared with an explosive which is not very sensitive in its action, such as trinitrotoluene, is used. I

Good uniform results have been obtained by a process which needs very careful exeto explode.

object of this invention is a system of branching which has the advanta cution and in the def by a trained and reliable operator, which the union is difficult to pro- Such process has also ect that it is not reversible, i. e., the

explosive wave cannot be transmitted. from the secondary branch to the main fuse.

It has also been the end fixed to the contact of the.

proposed to mount at of each secondary fuse a detonator, main fuse. This arrangement, though it may be sure in its action,

posed on the detonat is very dangerous, since it leaves exglround a large number of c ors whi the least shock may cause ge of being uniform in its action, not diflicult to use, absolutely safe, damp, and also reversible.

easily protected against According to this invention a union of any suitable shape is branch sections to be 1' partly provided with as many tubes as oined, and preferably only filled with high explosive, so as to insertion of the fuses or instance, to join a secondary fuse to the-main fuse, the latter is cut at the desired union isinserted in example, and filled with high explosive point, and a three-way the shape of a T, for ifih two ends of the main fuse may, for example, be piece 0 inserted into the ends f the T, and the end of thesecondary into the vertical. v

When several secondary fuses are to be connected. to the one fuses are to be connected main fuse, .orftwo 'main together, or other connection is to be made, a union of suitable .shape and with the of tubes is provided.

' Bythl the end instant required number of one of the leading in tubes is aneously and simultaneously transthere. are fuse lines or fuse of the cross 's means the explosion efi'ected at.

SeflaI' No. 708,112, and in France July 21, 1923.

mitted to the other to the fuse lihe's.

Any suitable high explosive, such as trinitrotoluene or melinite, may be used to fill the union piece and its sensitiveness need not necessarily be greater than the explosive contained in the fuse lines. I

The explosive wave is transmitted with absolute certainty and uniformity if care is taken so to fill the union piece that the average density of the charge is lower than that of the branched fuse lines. This condition is important if it is desired to obtain a very sensitive union while employing a very insensitive explosive.

It is also necessary to see that the union tubes have an internal equal to the external diameter of the covering of the fuse lines which should be able to enter the tubes. The section of explosive in the tubes should also be greater than the core of the fuse lines; this isalso a factor for aiding uniform transmission of the explosion. 4 Y

The fuse lines, which should be prefer-, ably cut off at right angles to their axes, when once introduced into the free space in the ends of each of the tubes and brought into contact with the high explosive, are held in place by contracting the end of the tube on to the fuse, or by any other suitable means. 5

As can be seen, the use of these union pieces is simple and quick, and within the scope of an unskilled workman.

To protect the union from damp, each se, where it enters the union tube, may be surrounded with a piece of insulating tape.

Ifthe union isifilled with an explosive less sensitive than that of the fuse, it has the advantage of being absolutely immune from external shocks, such as are caused by the fall of stones. I

As setout above, a wave produced at the end of-any one tube will to all the tubes of the union, 1. e., an exlosion may be transmitted in any direction.

The invention is illustrated in the. accompanying drawings, Figure lot which shows the invention inits most simple form, i. e., T union.

-Fig. 2 is a lan view of theinvention in the .form- 0 a cross; and Fig. 3 is a perspective of a further modification.

be transmitted diameter at least In this figure, 1 is a straight metal tube and 2 a tube led in at right angles thereto; tubes 1 and 2 are so filled with an explosive 3 that the end of each tube has a free portion 4 into which the ends of the fuses a b are introdured,

The union piece shown in Figure 2 is in the form of a cross, its four branches 5, 6, 7, 8, being similarly filled with explosive.

When several secondary fuses, all situated in the same plane at right angles to the main fuse, have to be connected to the one main fuse, the union piece shown in Figure 3 may be used.

This consists of a body 9 provided on one face with a tube 10 (or on two faces, according as to whether the main fuse stops at the union or is prolonged beyond the union) and circumferentially with as many tubes 11 as there are secondary fuses.

A union of this type may be used when it is desired to fire rapidly a number of charges at the bottom of a gallery in construction, each head being primed by a detonating fuse situated laterally to the charge and extending to the bottom of the head.

The union may be given any shape suitmaeao able for the number and arrangement. of the fuses.

What I claim is 1. A fuse union composed of a plurality of interconnected refractory tubes filled with a detonating explosive, except at the ends thereof.

2. In a fuse union, the combination with a plurality of interconnected refractory tubes, of detonating explosive in the tubes and fuses inserted in the ends of the tubes, the density of the charge being lower than that of the branched fuses.

3. A fuse union composed of a single tube and a plurality of interconnected tubes equally spaced from the single tube filled with a detonating explosive, except "at the ends thereof.

4. In a fuse union, the combination with a single tube and a plurality of interconnected tubes, equally spaced from the single tube, of detonating explosive in the tubes and fuses inserted in the ends of the tubes, the density of the charge being lower than that of the branched fuses.

In testimony whereof I have affixed my signature.

RICHARD MALLET. 

